М 42 Медведева, Н. И. Эффект давления на зонную структуру и Тс сверхпроводящего MgB2 [] / Н. И. Медведева // Новые неорганические материалы и химическая термодинамика: Второй семинар СО РАН - УрО РАН: Тез. докл. - 2002. - С. 142 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ЗОННАЯ СТРУКТУРА -- СТРУКТУРА ЗОННАЯ -- MgB2 -- БОРИД МАГНИЯ -- ВЫСОКОТЕМПЕРАТУРНАЯ СВЕРХПРОВОДИМОСТЬ -- СВЕРХПРОВОДИМОСТЬ ВЫСОКОТЕМПЕРАТУРНАЯ -- МЕТОД ЛМТО-СС -- ЭФФЕКТ ДАВЛЕНИЯ |
M 78 Moiseev, G. K. Thermodynamic Properties and Thermal Stability of Magnesium Borides [Text] / G. K. Moiseev, A. L. Ivanovskii // Inorganic Materials. - 2005. - Vol. 41, № 10. - P1061-1066 : il. - Библиогр. : с. 1065 (26 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): СВОЙСТВА ТЕРМОДИНАМИЧЕСКИЕ -- БОРИД МАГНИЯ Аннотация: Thermodynamic modeling (p = 9.8066´ 10–2 MPa, T = 300–2500 K) is used to assess the thermal stability of MgB12, Mg2B14, MgB6, MgB4, and MgB2. The thermodynamic properties and functions of MgB6 and Mg2B14 are calculated for the first time. The results are compared with earlier reported data Полный текст |
C 51 Chemical Shifts in the X-ray Emission Spectra of MgB2 and Their Correlation with the Electronic Structure [Текст] / N. I. Medvedeva, L. D. Finkelstein, S. N. Shamin, I. I. Lyakhovskaya, E. Z. Kurmaev // Physics of the Solid State . - 2004. - Vol. 46, № 11. - С. 1994-1997. - Библиогр. : с. 1997 (20 назв.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): БОРИД МАГНИЯ -- РЕНТГЕНОВСКАЯ ЭМИССИЯ Аннотация: The x-ray emission spectra of magnesium diboride MgB2 are measured. It is found that the Mg L2, 3 and B K a emission lines are shifted with respect to the spectra of the pure metals toward the low-energy range. The band calculations of the MgB2 diboride in the framework of the full-potential linearized muffin-tin orbital (LMTO) method demonstrate that the electron populations of the shells in both components of MgB2 are higher than those of pure metals. This increase in the electron populations is associated with the crystal contraction and manifests itself in low-energy shifts of the emission lines Полный текст |
E 43 Electronic States of Boron in Superconducting MgB 2Studied by "B NMR / A. P. Gerashenko, K. N. Mikhalev, S. V. Verkhovskii, T. V. D'yachkova, A. P. Tyutyunnik, V. G. Zubkov // Applied Magnetic Resonance. - 2001. - Vol. 21. - P. 157-163 : il. - Bibliogr. : p. 162-163 (12 ref.) . - ISSN 0937-9347 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): БОРИД МАГНИЯ -- СВЕРХПРОВОДИМОСТЬ -- ЯМР Аннотация: Nuclear magnetic resonance (NMR) spectra and nuclear spin-lattice relaxation rate T,' of 11B have been measured in superconducting polycrystalline Mg13 2 with T°"s = 39.5 K. It is shown that (T,T) (- 1) and the Knight shift K, are independent of temperature and nearly isotropic above 1. Both of these quantities are decreased gradually in going to the superconducting state. According to NMR data the density of states near the Fermi level is flat at the scale of about 500 K. Some conclusions on the orbital content of the density of states at the Fermi level were drawn and compared with the results of the band structure calculations Полный текст |